Brake



March 10, 1942. y M. w. BOWEN BRAKE A original'Fi-ied Feb. 2o, 19:56

INVENTOR. MyQo/v I/l/On/EN ATTORNEY.

Patented Mar. 1o, 1942 AUNITED STATES. PATENT OFFICE MyronW. Bowen,Niles, Mich., assignor to Hydraulic Brake Company, Detroit, Mich., acorporation `of California Original application February 10, 1936,Serial No. 64,929, now Patent No. 2,195,558, dated April 2, 1940.Divided and this application December 1, 1939, Serial No. 307,178

11 claims.. (ci. iso-54.6)

Thisapplication is a division of my co-pending application, Serial No.64,929, led February 10,

1936 now Patent No. 2,195,558, and is made in.

accordance with requirements of the United States Patent 'Office underprovision of Rule 42 This invention relates to vehicle brakes, and morespecifically to uid pressure actuated motors or wheel cylinders foractivating the friction elements or shoes of a brake.

An object of this invention is the provision of ai duplex iiuid pressureactuated motor for activating the friction elements of a brake operativethrough ya twinplex means, such as disclosed in my co-pendingapplication hereinabove referred to, or by duplex iiuid pressure brakingsystems operative concomitantly.

Another object of this invention is tor provide separate means forenergizing motors or Wheel cylinders for actuating the friction elementsof l a brake operative independently or concomi- A further object ofthis inventior is to provide a duplex fluid pressure actuated motoroperative to equalize the activative force or forces at the points ofapplication,

Other objects of the invention will appear fromrthe followingdescription taken in connection with the drawing whichiorms a part ofthis specification, and in which:

Fig. 1 is a vertical sectional view of a brake structure illustratingthe fluid pressure actuated motor in section; and

Fig. 2 is a sectional view substantially on line 2 2, Fig. 1.

Referring to the drawing for more speciiic de- 'A the friction elementsI4. 'The cylinder 20 has *f spaced inlet ports 22 and 24, and alsospaced ports 26 and' 28 connected by a passage 30 controlled as by ableeder screw 32 concealed by a plug V34.

A oating piston 36 in the cylinder 20 between the spaced ports hasoppositely disposed heads 38 and 40 provided with concentricdouble-diam- A etral extensions42 and 44, includingA opposed shoulders46 and 48, and sealing cups 59 and 52 sleeved on the extensions areseated on the heads of the piston 36. Oppositely disposed pistons 54 and56 reciprocable in the respective ends of the cylinder 2.0 have on theirheads extensions 59 and 60and sleeved on these extensions are sealingcups 62 and 64.

'I'he extensions 58V and 60 on the pistons 54 and 56 are bored for thereception. of the extensions 42 and 44 on` the heads of the iioatingpiston 36, and the free ends of the extensions 58 and 60 normally .abutthe shoulders 46 and 48 on`the extensions 42 and 44 of the floatingpiston. The pistons 54 and 56 have flanges 66 and 68 adapted to engagethe vrespective ends of the cylinders 20 so as to limit movement of thepistons in one direction. 'I'he pistons 54 and 56 also have recesses'land 'I2 'in their backs for the reception of adjustable thrust pins I4and 'I6 suitably connected 'to theA friction elements I4, and shields'I8 and 80 are connected between the thrust pins and the open ends ofthecylinder for the exclusion of dust and other foreign substances.

In a normal braking operation, delivery of `fluid under pressure from asuitable sourceinto the chambers of the motor causes energi'zation ofthe motor, `causing actuation of the pistons 54 and 56. This actuationof the pistons 54 and 56 moves the shoes I4 into engagement with thedrum I2 against-'the resistance of the retractile spring I8. Due totheoating piston 36 between the pistons 54 and 56, the pressures on theiiuid the chambers ofthe motor are equalized so that the shoes I4 may beapplied with equal force. "nf

During a braking application, should there occur a loss in the source ofsupply of fluid under pressure to either of the chambers of the motor,

due to leakage or other causes, the oating -piston shifts to abut andactate the piston in the chamber,` sustaining the loss of pressure onthe It is, of course, to be understood that fluid under pressure may bedelivered inthe respective chambers of the motor simultaneously orsuccessively, as -in instances where it is desirable to eiect a lightbraking application followed by a4` heavy braking application, orv thatuid under pressure may be delivered to one only of the chambers of themotor at a time for actuating the brakes as service and parking brakes.

,Although this invention has-been described in connection with certain',specific embodimen the principles involved are'susceptible of numerousother applications that will readily occur to persons skilled inV theart. The invention is, therefore, to be limited only as indicated by thescope of the appended claims.

Having thus described the various featuresxof the invention, what Iclaim as new and desire to secure by `Letters Patent is: l p 1. A duplexfluid pressure actuated motor for activating oppositely positionedelements, said motor including a cylinder, opposed pistons in thcylinder, and a member floating within'the cylinder between the pistons.

2. A duplex fluid pressure motor connected to oppositely arrangedelements for, the actuation thereof, said motor including a cylinder,opposed within thecylinder between the pistons having parts telescopedby thepistons.

terconnected with the pistons.

4. A cylinder centrally of a pair of oppositely arranged elements havingspaced ports, opposed pistons reciprocable in the cylinder, and a memberreciprocable in the cylinders between the ports pistons. v

5. A uid actuated motor including a cylinder,

pistons in the cylinder, and a member iloating 7. A cylinder nxedlysupported between oppositely arranged elements, opposed pistonsconnected to the elements reciprocable in the cylinder, a memberfloating within the cylinder between the opposed pistons, and meansextending between said member and each of the pistons whereby eitherpiston 1may be actuated by the member. f

8. A cylinder ilxedly supported between oppositely arranged elements,opposed pistons recipof the pistons.

having parts slidably engaging and abutting the opposed pistonsreciprocable in the cylinder for activating oppositely arrangedelements, 'and a piston floating within the cylinder between the opposedpistons to actuate the opposed pistons.

10. A cylinder positioned between a pair of elements, spaced ports inthe cylinder, opposed pistons reciprocable in the cylinder, a floatingmember intermediate the spaced ports providing chambers in conjunctionwith the pistons, said ports communicating directly with theirrespective chambers.. and means inthel chambers connecting the memberand pistons'for the respective actuation thereof. n

11'. A duplex nuid pressure actuated motor for actuating oppositelypositioned elements, said motor including a cylinder, opposed pistons inthe cylinder, said cylinder provided with spaced inlet ports, a memberfloating within the cylinder between the ports and engaging each of theopposed pistons to position the same, and mov- 40 piston. i

